Systematic information concerning sexual, marital and social experience was obtained by structured interviews with males taking part in the GRC longitudinal study of aging. In the present analysis, limited to over 500 subjects aged 40-79 at report, correlations were computed between many of the variables derived from the interview in order to develop a statistical description of the structural features of the male sexual life history. Major findings include the demonstration of a substantial negative correlation between age at first coitus and number of coital partners before age 40, as well as a general lack of correlation between number of partners and measures of sex drive as had been assumed. The best predictor of sex drive proved to be respondent estimates of frequency of coitus in the first year or two of marriage. From the perspective of etiologic inquiry, future plans are to relate the various variables obtained from interviews to such diagnostic entities as coronary artery disease, hyperlipidemia and other diseases and disabilities.